As previously reported, Apple's offer gives a $300 rebate to consumers who buy the Cube along with an Apple monitor and a $200 rebate on its PowerBook line of notebook computers.
The move follows Apple's warning two weeks ago that sales in the recently completed quarter would be "substantially below expectations" because of weak September sales.
The offer is good only for computers bought starting today, not prior purchases, Apple said. The deal is available through both resellers and Apple's online store but not for those buying under Apple's education pricing programs.
"We want to encourage even more people to experience how great personal computing can be using an Apple PowerBook or G4 Cube," an Apple spokeswoman said. Apple declined to comment on the financial effect of the rebates, citing a quiet period before it releases earnings next week.
With the rebate, the price of the lowest-end Cube drops to $1,499, not including a monitor. The eligible screens range from Apple's $499 17-inch CRT monitor to the $3,999 22-inch, flat-screen Cinema Display.
Gerard Klauer Mattison analyst David Bailey earlier this week said he would welcome a move such as a rebate, which could improve Apple's position going into the all-important holiday buying season.
"It appears that initial weak demand for the Cube was somewhat caused by the price being high," Bailey said.
The Cube has also been criticized for blemishes that some have called cracks. Apple has maintained the marks are "mold lines" that are part of the normal manufacturing process.